View Compilation Error

0_0_12918140_24681.cpp: In function `int main()':
0_0_12918140_24681.cpp:12: error: `x' undeclared (first use this function)
0_0_12918140_24681.cpp:12: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_12918140_24681.cpp:13: error: `y' undeclared (first use this function)
0_0_12918140_24681.cpp:14: error: `z' undeclared (first use this function)